1. WeatherSpark.com
  2. Sweden
  3. Södermanland

Climate and Average Weather Year Round in Trosa Sweden

In Trosa, the summers are comfortable and partly cloudy and the winters are long, freezing, dry, and mostly cloudy. Over the course of the year, the temperature typically varies from 23°F to 71°F and is rarely below 7°F or above 79°F.

Based on the tourism score, the best time of year to visit Trosa for warm-weather activities is from late June to mid August.

Climate in Trosa

very coldcoldcoolcomfortablecoolcoldvery coldJanFebMarAprMayJunJulAugSepOctNovDecNowNow57%57%26%26%overcastclearprecipitation: 2.2 inprecipitation: 2.2 in0.8 in0.8 inmuggy: 2%muggy: 2%0%0%drydrytourism score: 6.8tourism score: 6.80.00.0
Trosa weather by month. Click on each chart for more information.

Average Temperature in Trosa

The warm season lasts for 3.0 months, from June 6 to September 5, with an average daily high temperature above 63°F. The hottest day of the year is July 22, with an average high of 71°F and low of 55°F.

The cold season lasts for 4.0 months, from November 20 to March 20, with an average daily high temperature below 40°F. The coldest day of the year is February 10, with an average low of 23°F and high of 32°F.

Average High and Low Temperature in Trosa

Average High and Low Temperature in TrosawarmcoldcoldJanFebMarAprMayJunJulAugSepOctNovDec0°F0°F10°F10°F20°F20°F30°F30°F40°F40°F50°F50°F60°F60°F70°F70°F80°F80°F90°F90°F100°F100°FFeb 1032°FFeb 1032°FJul 2271°FJul 2271°F23°F23°F55°F55°FJun 663°FJun 663°FSep 563°FSep 563°FNov 2040°FNov 2040°FMar 2040°FMar 2040°F46°F46°F49°F49°F32°F32°F27°F27°FNowNow
The daily average high (red line) and low (blue line) temperature, with 25th to 75th and 10th to 90th percentile bands. The thin dotted lines are the corresponding average perceived temperatures.

The figure below shows you a compact characterization of the entire year of hourly average temperatures. The horizontal axis is the day of the year, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.

Average Hourly Temperature in Trosa

Average Hourly Temperature in TrosaJanFebMarAprMayJunJulAugSepOctNovDec12 AM12 AM4 AM4 AM8 AM8 AM12 PM12 PM4 PM4 PM8 PM8 PM12 AM12 AMNowNowfreezingvery coldvery coldcoldcoldcoolcomfortablefreezing
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
The average hourly temperature, color coded into bands. The shaded overlays indicate night and civil twilight.

Terrace, Canada (4,383 miles away) and Shelburne, Canada (3,480 miles) are the far-away foreign places with temperatures most similar to Trosa (view comparison).

Compare Trosa to another city:

Clouds

In Trosa, the average percentage of the sky covered by clouds experiences significant seasonal variation over the course of the year.

The clearer part of the year in Trosa begins around April 21 and lasts for 5.6 months, ending around October 10. On July 18, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 57% of the time, and overcast or mostly cloudy 43% of the time.

The cloudier part of the year begins around October 10 and lasts for 6.4 months, ending around April 21. On November 27, the cloudiest day of the year, the sky is overcast or mostly cloudy 74% of the time, and clear, mostly clear, or partly cloudy 26% of the time.

Cloud Cover Categories in Trosa

Cloud Cover Categories in TrosaclearercloudiercloudierJanFebMarAprMayJunJulAugSepOctNovDec0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%Jul 1857%Jul 1857%Nov 2726%Nov 2726%Apr 2142%Apr 2142%Oct 1042%Oct 1042%NowNowclearmostly clearpartly cloudymostly cloudyovercast
0% clear 20% mostly clear 40% partly cloudy 60% mostly cloudy 80% overcast 100%
The percentage of time spent in each cloud cover band, categorized by the percentage of the sky covered by clouds.

Precipitation

A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Trosa varies throughout the year.

The wetter season lasts 7.0 months, from June 6 to January 4, with a greater than 24% chance of a given day being a wet day. The chance of a wet day peaks at 30% on November 14.

The drier season lasts 5.0 months, from January 4 to June 6. The smallest chance of a wet day is 17% on February 27.

Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 28% on October 22.

Daily Chance of Precipitation in Trosa

Daily Chance of Precipitation in TrosawetdryJanFebMarAprMayJunJulAugSepOctNovDec0%0%10%10%20%20%30%30%40%40%50%50%60%60%70%70%80%80%90%90%100%100%Nov 1430%Nov 1430%Feb 2717%Feb 2717%Jan 125%Jan 125%Jun 624%Jun 624%Jan 424%Jan 424%NowNowrainsnow
The percentage of days in which various types of precipitation are observed, excluding trace quantities: rain alone, snow alone, and mixed (both rain and snow fell in the same day).

Rainfall

To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day of the year. Trosa experiences some seasonal variation in monthly rainfall.

Rain falls throughout the year in Trosa. The most rain falls during the 31 days centered around July 11, with an average total accumulation of 2.2 inches.

The least rain falls around February 24, with an average total accumulation of 0.6 inches.

Average Monthly Rainfall in Trosa

Average Monthly Rainfall in TrosaJanFebMarAprMayJunJulAugSepOctNovDec0 in0 in1 in1 in2 in2 in3 in3 in4 in4 inJul 112.2 inJul 112.2 inFeb 240.6 inFeb 240.6 inOct 291.8 inOct 291.8 inNowNow
The average rainfall (solid line) accumulated over the course of a sliding 31-day period centered on the day in question, with 25th to 75th and 10th to 90th percentile bands. The thin dotted line is the corresponding average liquid-equivalent snowfall.

Snowfall

We report snowfall in liquid-equivalent terms. The actual depth of new snowfall is typically between 5 and 10 times the liquid-equivalent amount, assuming the ground is frozen. Colder, drier snow tends to be on the higher end of that range and warmer, wetter snow on the lower end.

As with rainfall, we consider the snowfall accumulated over a sliding 31-day period centered around each day of the year. Trosa experiences some seasonal variation in monthly liquid-equivalent snowfall.

The snowy period of the year lasts for 4.5 months, from November 16 to March 31, with a sliding 31-day liquid-equivalent snowfall of at least 0.1 inches. The most snow falls during the 31 days centered around February 6, with an average total liquid-equivalent accumulation of 0.3 inches.

The snowless period of the year lasts for 7.5 months, from March 31 to November 16. The least snow falls around July 25, with an average total liquid-equivalent accumulation of 0.0 inches.

Average Liquid-Equivalent Monthly Snowfall in Trosa

Average Liquid-Equivalent Monthly Snowfall in TrosasnowsnowJanFebMarAprMayJunJulAugSepOctNovDec0.0 in0.0 in0.5 in0.5 in1.0 in1.0 in1.5 in1.5 in2.0 in2.0 in2.5 in2.5 inFeb 60.3 inFeb 60.3 inJul 250.0 inJul 250.0 inDec 220.3 inDec 220.3 inMar 310.1 inMar 310.1 inNowNow
The average liquid-equivalent snowfall (solid line) accumulated over the course of a sliding 31-day period centered on the day in question, with 25th to 75th and 10th to 90th percentile bands. The thin dotted line is the corresponding average rainfall.

Sun

The length of the day in Trosa varies extremely over the course of the year. In 2021, the shortest day is December 21, with 6 hours, 12 minutes of daylight; the longest day is June 21, with 18 hours, 28 minutes of daylight.

Hours of Daylight and Twilight in Trosa

Hours of Daylight and Twilight in TrosaJanFebMarAprMayJunJulAugSepOctNovDec0 hr24 hr4 hr20 hr8 hr16 hr12 hr12 hr16 hr8 hr20 hr4 hr24 hr0 hr12 hr, 8 minMar 2012 hr, 8 minMar 2018 hr, 28 minJun 2118 hr, 28 minJun 2112 hr, 15 minSep 2212 hr, 15 minSep 226 hr, 12 minDec 216 hr, 12 minDec 21nightnightdayNowNow
The number of hours during which the Sun is visible (black line). From bottom (most yellow) to top (most gray), the color bands indicate: full daylight, twilight (civil, nautical, and astronomical), and full night.

The earliest sunrise is at 3:37 AM on June 18, and the latest sunrise is 5 hours, 6 minutes later at 8:43 AM on December 27. The earliest sunset is at 2:52 PM on December 15, and the latest sunset is 7 hours, 13 minutes later at 10:05 PM on June 23.

Daylight saving time (DST) is observed in Trosa during 2021, starting in the spring on March 28, lasting 7.1 months, and ending in the fall on October 31.

Sunrise & Sunset with Twilight and Daylight Saving Time in Trosa

Sunrise & Sunset with Twilight and Daylight Saving Time in TrosaJanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AMJun 183:37 AMJun 183:37 AM10:05 PMJun 2310:05 PMJun 23Dec 152:52 PMDec 152:52 PM8:43 AMDec 278:43 AMDec 27Mar 28DSTMar 28DSTDSTOct 31DSTOct 31daynightnightnightnightSolarMidnightSolarMidnightSolarNoonSunriseSunsetNowNow
The solar day over the course of the year 2021. From bottom to top, the black lines are the previous solar midnight, sunrise, solar noon, sunset, and the next solar midnight. The day, twilights (civil, nautical, and astronomical), and night are indicated by the color bands from yellow to gray. The transitions to and from daylight saving time are indicated by the 'DST' labels.

Moon

The figure below presents a compact representation of key lunar data for 2021. The horizontal axis is the day, the vertical axis is the hour of the day, and the colored areas indicate when the moon is above the horizon. The vertical gray bars (new Moons) and blue bars (full Moons) indicate key Moon phases.

Moon Rise, Set & Phases in Trosa

The time in which the moon is above the horizon (light blue area), with new moons (dark gray lines) and full moons (blue lines) indicated. The shaded overlays indicate night and civil twilight.

Humidity

We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.

The perceived humidity level in Trosa, as measured by the percentage of time in which the humidity comfort level is muggy, oppressive, or miserable, does not vary significantly over the course of the year, staying within 1% of 1% throughout.

Humidity Comfort Levels in Trosa

Humidity Comfort Levels in TrosaJanFebMarAprMayJunJulAugSepOctNovDec0%0%10%10%20%20%30%30%40%40%50%50%60%60%70%70%80%80%90%90%100%100%Nov 110%Nov 110%Aug 12%Aug 12%NowNowcomfortablecomfortabledrydryhumidhumid
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
The percentage of time spent at various humidity comfort levels, categorized by dew point.

Wind

This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.

The average hourly wind speed in Trosa experiences mild seasonal variation over the course of the year.

The windier part of the year lasts for 6.5 months, from September 6 to March 20, with average wind speeds of more than 7.7 miles per hour. The windiest day of the year is December 31, with an average hourly wind speed of 9.2 miles per hour.

The calmer time of year lasts for 5.5 months, from March 20 to September 6. The calmest day of the year is June 24, with an average hourly wind speed of 6.3 miles per hour.

Average Wind Speed in Trosa

Average Wind Speed in TrosawindywindyJanFebMarAprMayJunJulAugSepOctNovDec0 mph0 mph2 mph2 mph4 mph4 mph6 mph6 mph8 mph8 mph10 mph10 mph12 mph12 mphDec 319.2 mphDec 319.2 mphJun 246.3 mphJun 246.3 mphSep 67.7 mphSep 67.7 mphMar 207.7 mphMar 207.7 mphNowNow
The average of mean hourly wind speeds (dark gray line), with 25th to 75th and 10th to 90th percentile bands.

The predominant average hourly wind direction in Trosa varies throughout the year.

The wind is most often from the south for 2.4 months, from April 6 to June 19, with a peak percentage of 33% on May 10. The wind is most often from the west for 9.6 months, from June 19 to April 6, with a peak percentage of 42% on January 1.

Wind Direction in Trosa

Wind Direction in TrosaWSWJanFebMarAprMayJunJulAugSepOctNovDec0%100%20%80%40%60%60%40%80%20%100%0%NowNowwestsoutheastnorth
northeastsouthwest
The percentage of hours in which the mean wind direction is from each of the four cardinal wind directions, excluding hours in which the mean wind speed is less than 1.0 mph. The lightly tinted areas at the boundaries are the percentage of hours spent in the implied intermediate directions (northeast, southeast, southwest, and northwest).

Water Temperature

Trosa is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.

The average water temperature experiences significant seasonal variation over the course of the year.

The time of year with warmer water lasts for 2.5 months, from June 29 to September 15, with an average temperature above 57°F. The day of the year with the warmest water is August 6, with an average temperature of 63°F.

The time of year with cooler water lasts for 4.6 months, from December 15 to May 1, with an average temperature below 40°F. The day of the year with the coolest water is March 2, with an average temperature of 34°F.

Average Water Temperature in Trosa

Average Water Temperature in TrosawarmcoolJanFebMarAprMayJunJulAugSepOctNovDec30°F30°F35°F35°F40°F40°F45°F45°F50°F50°F55°F55°F60°F60°F65°F65°F70°F70°FAug 663°FAug 663°F34°FMar 234°FMar 2Jun 2957°FJun 2957°FSep 1557°FSep 1557°FDec 1540°FDec 1540°FMay 140°FMay 140°FNowNow
The daily average water temperature (purple line), with 25th to 75th and 10th to 90th percentile bands.

Best Time of Year to Visit

To characterize how pleasant the weather is in Trosa throughout the year, we compute two travel scores.

The tourism score favors clear, rainless days with perceived temperatures between 65°F and 80°F. Based on this score, the best time of year to visit Trosa for general outdoor tourist activities is from late June to mid August, with a peak score in the third week of July.

Tourism Score in Trosa

Tourism Score in Trosabest timeJanFebMarAprMayJunJulAugSepOctNovDec002244668810106.86.80.00.0NowNowprecipitationprecipitationcloudscloudstemperaturetemperature tourism score
The tourism score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best time of year to visit Trosa for hot-weather activities is from mid July to early August, with a peak score in the third week of July.

Beach/Pool Score in Trosa

Beach/Pool Score in TrosaJanFebMarAprMayJunJulAugSepOctNovDec002244668810102.92.90.00.0NowNowprecipitationprecipitationcloudscloudstemperaturetemperature
The beach/pool score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

Methodology

For each hour between 8:00 AM and 9:00 PM of each day in the analysis period (1980 to 2016), independent scores are computed for perceived temperature, cloud cover, and total precipitation. Those scores are combined into a single hourly composite score, which is then aggregated into days, averaged over all the years in the analysis period, and smoothed.

Our cloud cover score is 10 for fully clear skies, falling linearly to 9 for mostly clear skies, and to 1 for fully overcast skies.

Our precipitation score, which is based on the three-hour precipitation centered on the hour in question, is 10 for no precipitation, falling linearly to 9 for trace precipitation, and to 0 for 0.04 inches of precipitation or more.

Our tourism temperature score is 0 for perceived temperatures below 50°F, rising linearly to 9 for 65°F, to 10 for 75°F, falling linearly to 9 for 80°F, and to 1 for 90°F or hotter.

Our beach/pool temperature score is 0 for perceived temperatures below 65°F, rising linearly to 9 for 75°F, to 10 for 82°F, falling linearly to 9 for 90°F, and to 1 for 100°F or hotter.

Growing Season

Definitions of the growing season vary throughout the world, but for the purposes of this report, we define it as the longest continuous period of non-freezing temperatures (≥ 32°F) in the year (the calendar year in the Northern Hemisphere, or from July 1 until June 30 in the Southern Hemisphere).

The growing season in Trosa typically lasts for 5.0 months (154 days), from around May 8 to around October 9, rarely starting before April 21 or after May 24, and rarely ending before September 19 or after October 31.

Time Spent in Various Temperature Bands and the Growing Season in Trosa

Time Spent in Various Temperature Bands and the Growing Season in Trosagrowing seasonJanFebMarAprMayJunJulAugSepOctNovDec0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%May 850%May 850%Oct 950%Oct 950%May 2490%May 2490%Sep 1990%Sep 1990%Apr 2110%Apr 2110%Oct 3110%Oct 3110%Jul 21100%Jul 21100%NowNowfrigidfreezingvery coldcoldcoolcomfortable
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
The percentage of time spent in various temperature bands. The black line is the percentage chance that a given day is within the growing season.

Growing degree days are a measure of yearly heat accumulation used to predict plant and animal development, and defined as the integral of warmth above a base temperature, discarding any excess above a maximum temperature. In this report, we use a base of 50°F and a cap of 86°F.

Based on growing degree days alone, the first spring blooms in Trosa should appear around May 21, only rarely appearing before May 12 or after June 1.

Growing Degree Days in Trosa

Growing Degree Days in TrosaJanFebMarAprMayJunJulAugSepOctNovDec0°F0°F200°F200°F400°F400°F600°F600°F800°F800°F1,000°F1,000°F1,200°F1,200°F1,400°F1,400°FMay 2190°FMay 2190°FAug 9900°FAug 9900°FDec 311,313°FDec 311,313°FNowNow
The average growing degree days accumulated over the course of the year, with 25th to 75th and 10th to 90th percentile bands.

Solar Energy

This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.

The average daily incident shortwave solar energy experiences extreme seasonal variation over the course of the year.

The brighter period of the year lasts for 3.2 months, from May 4 to August 10, with an average daily incident shortwave energy per square meter above 5.0 kWh. The brightest day of the year is June 21, with an average of 6.2 kWh.

The darker period of the year lasts for 4.3 months, from October 17 to February 26, with an average daily incident shortwave energy per square meter below 1.4 kWh. The darkest day of the year is December 20, with an average of 0.2 kWh.

Average Daily Incident Shortwave Solar Energy in Trosa

Average Daily Incident Shortwave Solar Energy in TrosabrightdarkdarkJanFebMarAprMayJunJulAugSepOctNovDec0 kWh0 kWh1 kWh1 kWh2 kWh2 kWh3 kWh3 kWh4 kWh4 kWh5 kWh5 kWh6 kWh6 kWh7 kWh7 kWh8 kWh8 kWh9 kWh9 kWhJun 216.2 kWhJun 216.2 kWhDec 200.2 kWhDec 200.2 kWhMay 45.0 kWhMay 45.0 kWhAug 105.0 kWhAug 105.0 kWhOct 171.4 kWhOct 171.4 kWhFeb 261.4 kWhFeb 261.4 kWhNowNow
The average daily shortwave solar energy reaching the ground per square meter (orange line), with 25th to 75th and 10th to 90th percentile bands.

Topography

For the purposes of this report, the geographical coordinates of Trosa are 58.896 deg latitude, 17.548 deg longitude, and 26 ft elevation.

The topography within 2 miles of Trosa contains only modest variations in elevation, with a maximum elevation change of 194 feet and an average elevation above sea level of 54 feet. Within 10 miles also contains only modest variations in elevation (318 feet). Within 50 miles contains only modest variations in elevation (574 feet).

The area within 2 miles of Trosa is covered by trees (42%), cropland (30%), water (14%), and artificial surfaces (13%), within 10 miles by trees (40%) and water (40%), and within 50 miles by water (52%) and trees (29%).

Data Sources

This report illustrates the typical weather in Trosa, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.

Temperature and Dew Point

There are 4 weather stations near enough to contribute to our estimation of the temperature and dew point in Trosa.

For each station, the records are corrected for the elevation difference between that station and Trosa according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations.

The estimated value at Trosa is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Trosa and a given station.

The stations contributing to this reconstruction are: Tullinge (ESCN, 42%, 38 kilometers, northeast); Stockholm Skavsta Airport (ESKN, 41%, 39 kilometers, west); Stockholm-Västerås Airport (ESOW, 11%, 93 kilometers, northwest); and Visby Airport (ESSV, 6%, 145 kilometers, south).

Other Data

All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Algorithms 2nd Edition , by Jean Meeus.

All other weather data, including cloud cover, precipitation, wind speed and direction, and solar flux, come from NASA's MERRA-2 Modern-Era Retrospective Analysis . This reanalysis combines a variety of wide-area measurements in a state-of-the-art global meteorological model to reconstruct the hourly history of weather throughout the world on a 50-kilometer grid.

Land Use data comes from the Global Land Cover SHARE database , published by the Food and Agriculture Organization of the United Nations.

Elevation data comes from the Shuttle Radar Topography Mission (SRTM) , published by NASA's Jet Propulsion Laboratory.

Names, locations, and time zones of places and some airports come from the GeoNames Geographical Database .

Time zones for airports and weather stations are provided by AskGeo.com .

Maps are © Esri, with data from National Geographic, Esri, DeLorme, NAVTEQ, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, and iPC.

Disclaimer

The information on this site is provided as is, without any assurances as to its accuracy or suitability for any purpose. Weather data is prone to errors, outages, and other defects. We assume no responsibility for any decisions made on the basis of the content presented on this site.

We draw particular cautious attention to our reliance on the MERRA-2 model-based reconstructions for a number of important data series. While having the tremendous advantages of temporal and spatial completeness, these reconstructions: (1) are based on computer models that may have model-based errors, (2) are coarsely sampled on a 50 km grid and are therefore unable to reconstruct the local variations of many microclimates, and (3) have particular difficulty with the weather in some coastal areas, especially small islands.

We further caution that our travel scores are only as good as the data that underpin them, that weather conditions at any given location and time are unpredictable and variable, and that the definition of the scores reflects a particular set of preferences that may not agree with those of any particular reader.